The Essentials of Patient Safety - Clinical Human Factors Group

The Essentials of Patient Safety
Many adverse drug events occur outside hospital, often then leading to
hospital admission. For instance, in Boston Tejal Gandhi and colleagues reviewed 661
out patients on a variety of drug regimens (10). Incredibly, almost a quarter of these
people were assessed as suffering adverse drug reactions and about 6% of the patients
were suffering serious reactions. Serious adverse drug reactions included bradycardia,
hypotension and gastrointestinal bleeding, many of which were clearly preventable.
Other consequences were less serious, in that they did not present immediate threats
to life, but were certainly serious for the patient. For instance, one patient suffered
prolonged sexual dysfunction after his doctor failed to stop a selective serotonin
uptake inhibitor; another had continued sleep disturbance due to taking an antidepressant
that his doctor was not aware of. Such reactions represent prolonged,
avoidable suffering over many months, to say nothing of the waste of time and
resources.
The impact and cost of adverse events
The majority of adverse events, about 70% in most studies, do not have serious
consequences for the patient; the effects of minor events may be more economic, in
the sense of wasted time and resources, than clinical (6). Some, such as the reaction
to anaesthetic, are not serious for the patient but are classed as an adverse event
because there was an increased stay in hospital of one day; it was probably not
preventable in that it would have been hard to predict such an idiosyncratic reaction.
Others however, as the remaining examples show, cause considerable unnecessary
suffering and extended time in hospital.
In Britain the cost of preventable adverse events is £1 billion per annum in lost
bed days alone as, on average, an adverse event leads to an extra week in hospital
(11). The Institute of Medicine report (1999) was able to estimate that in the United
States the total national costs associated with adverse events and preventable adverse
events represent approximately 4% and 2% respectively of national health
expenditure (12). Costs of direct hospital care, essentially additional time in hospital,
have recently been estimated from the Dutch adverse events study finding that about
3% of all bed days and 1% of the total health budget could be attributed to
preventable adverse events (13). The real overall costs are probably a good deal
higher, as these estimates do not include additional treatments and investigations or
any of the associated societal costs discussed above. Remember also that these
estimates are confined to the hospital sector; we have no idea of the additional costs
of adverse events in primary care or mental health.
The human cost of adverse events is the greatest of all. Many patients suffer
increased pain and disability from serious adverse events. They often also suffer
psychological trauma and may experience failures in their treatment as a terrible betrayal
of trust. Staff may experience shame, guilt and depression after making a mistake with
litigation and complaints imposing an additional burden (14). These profoundly
important aspects of patient safety, generally given far too little attention, are considered
later.
Vulnerability to harm: the old and the frail
Curiously, relatively little attention has been paid to patient safety in older people
although they are particularly vulnerable to healthcare error and harm, as are the very
young (15). Most people in hospital are old. In Britain for instance patients over 65,
mostly with multiple long term conditions, account for about 60% of admissions and
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